From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r05sS0H7DzDqGM for ; Wed, 4 May 2016 15:18:03 +1000 (AEST) Received: from localhost by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 May 2016 14:47:43 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 4D8D33578057 for ; Wed, 4 May 2016 14:47:39 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u444lVeh65405016 for ; Wed, 4 May 2016 14:47:39 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u444l6KE003055 for ; Wed, 4 May 2016 14:47:06 +1000 From: "Ian Munsie" To: Michael Ellerman , mikey , Cc: Ian Munsie Subject: [PATCH] cxl: Handle num_of_processes larger than can fit in the SPA Date: Wed, 4 May 2016 14:46:30 +1000 Message-Id: <1462337190-13230-1-git-send-email-imunsie@au.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Ian Munsie num_of_process is a 16 bit field, theoretically allowing an AFU to support 16K processes, however the scheduled process area currently has a maximum size of 1MB, which limits the maximum number of processes to 7704. Some AFUs may not necessarily care what the limit is and just want to be able to use the maximum by setting the field to 16K. To allow these to work, detect this situation and use the maximum size for the SPA. Downgrade the WARN_ON to a dev_warn. Signed-off-by: Ian Munsie --- drivers/misc/cxl/native.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c index 387fcbd..b8b547a 100644 --- a/drivers/misc/cxl/native.c +++ b/drivers/misc/cxl/native.c @@ -185,16 +185,25 @@ static int spa_max_procs(int spa_size) int cxl_alloc_spa(struct cxl_afu *afu) { + unsigned spa_size; + /* Work out how many pages to allocate */ afu->native->spa_order = 0; do { afu->native->spa_order++; - afu->native->spa_size = (1 << afu->native->spa_order) * PAGE_SIZE; + spa_size = (1 << afu->native->spa_order) * PAGE_SIZE; + + if (spa_size > 0x100000) { + dev_warn(&afu->dev, "num_of_processes too large for the SPA, limiting to %i (0x%x)\n", + afu->native->spa_max_procs, afu->native->spa_size); + afu->num_procs = afu->native->spa_max_procs; + break; + } + + afu->native->spa_size = spa_size; afu->native->spa_max_procs = spa_max_procs(afu->native->spa_size); } while (afu->native->spa_max_procs < afu->num_procs); - WARN_ON(afu->native->spa_size > 0x100000); /* Max size supported by the hardware */ - if (!(afu->native->spa = (struct cxl_process_element *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, afu->native->spa_order))) { pr_err("cxl_alloc_spa: Unable to allocate scheduled process area\n"); -- 2.1.4